December 18, 2025
Dear Community Members and Families of the Aliso Canyon Disaster area,
Season’s greetings! We wish you happy holidays and hope this letter finds you well. We recently shared an extensive mid-year letter that highlighted our significant progress on meeting major study milestones including:
- Two newly published studies;
- Studies being prepared for submission to peer-reviewed journals;
- Other health and exposure studies that are in progress;
- The upcoming Scientific Oversight Committee (SOC) review of the study’s progress;
- Community engagement activities including community meeting #5, website updates, engagement with the study Community Engagement Support and Advice Network (CESAN); and
- Preparation for the launch of the Resident Health Survey and Clinical Assessments.
We are now writing to update you on additional progress and updates since the mid-year letter.
Launch of the Resident Health Survey and Clinical Assessments
In preparation for the launch of the survey, we participated in the Granada Hills Chamber of Commerce’s Granada Hills Street Faire to raise awareness of the launch of the survey and clinical assessments and answer community questions. We also participated in the Aliso Canyon 10-Year Anniversary Townhall to raise awareness and answer community questions about the overall study.
The survey was officially launched in late October with over 256 completed surveys and 42 clinical assessments scheduled or completed as of the date of this letter. Additional invitation letters and reminders will be mailed until 2,000 surveys and 600 clinical assessments are completed.
Please continue to watch your mailbox for a potential invitation letter at your home address to participate in the survey and remind your neighbors to do the same. Every household has a chance to be selected. If you receive the letter, please respond promptly and respond to the clinical assessment consent question at the end of the survey.
Upcoming Study and Community Engagement Activities
We submitted our progress report to the Scientific Oversight Committee (SOC) on December 11, 2025.
Community Meeting #6
We held Community Meeting #6 on November 18, 2025, during which the research team reported on the status of the Resident Health Survey and Clinical Assessments, shared preliminary findings of two studies, and provided other study updates. The preliminary studies presented were:
- Indoor and outdoor air sampling at homes in the affected and comparison communities. This analysis was conducted to identify if there are elevated air pollutant levels in the affected community and whether these exceeded health protective standards.
- Natural gas sampling conducted to help understand the composition of natural gas from the Aliso Canyon facility and inform exposure analyses. It also provides information about potential indoor benzene concentrations if a natural gas appliance leaks.
We appreciate all of the community’s questions and feedback received, which continue to inform and improve the study.
We will continue with biannual community meetings in 2026 to share study updates and preliminary results as they become available, and to hear community feedback.
Wishing you a joyous holiday season and happy New Year,
UCLA Aliso Canyon Disaster Health Research Study Team and Partners
